RESUMO
The paper presents the experimental studies on the effect of the water containing micro-nano bubbles of various gases on the physico-mechanical properties of lime-cement mortars. In total, 7 types of mortars were prepared: with water containing the micro-nano bubbles of O2, O3 or CO2 as 50% or 100% substitute of ordinary mixing water (tap water) and the reference mortar prepared using tap water. In order to determine the influence of water with micro-nano bubbles of gases, the consistency of fresh mortar and the physical properties of hardened mortar, i.e., specific and apparent density, total porosity, water absorption by weight and capillary absorption, were established. The mechanical strength of the considered mortars was studied as well by conducting the tests for flexural and compressive strengths following 14, 28 and 56 days. Reduced workability and capillary absorption were observed in the modified mortars within the range of 0.9-8.5%. The mortars indicated an increase in the flexural strength after 28 days ranging from 3.4% to 23.5% and improved compressive strength in 1.2-31%, in comparison to the reference mortar. The conducted studies indicated increased flexural and compressive strengths along with the share of micro-nano bubbles of gases in the mixing water.
RESUMO
INTRODUCTION: The health behaviors or health-related behaviors is behavior (or activity) that are part of everyday life, affecting the health of the individual. An example of the behavior of health is also sunbathing, or exposing the body to excessive solar radiation dosage. It may be positive and negative effects on health. AIM: Evaluation of knowledge about gymnasium students. The impact of UV radiation on health and health behaviors associated with sunbathing. MATERIAL AND METHODS: The study was a diagnostic survey, with author's questionnaire. The sample was comprised students from classes II and III. A total of 312 questionnaires were collected among 181 girls and 131 boys. Used purposeful sampling. Results were considered statistically significant at p < 0.05. RESULTS: There is a statistically significant relationship between the stated sunbathing to get a sun tan, and sex of the respondent (p = 0.0002). Definitely more girls (77.35%) admit that tans in the sun to get a tan as compared to boys (58.02%). CONCLUSION: It is recommended that further research aimed at checking the causes and incidence of sunburn among young people. Consideration should be given to create and implement the appropriate health programs taking about tanning that could be implemented under the School Health Promotion Program, or to supplement this knowledge on subjects such as Biology or Nature.
